采用双卫星导航系统的精密单点定位精度研究

摘要

使用自主开发的软件解算天津连续运行参考站三系统观测数据，比较分析了全球定位系统、北斗系统及其组合三种方式的静态精密单点定位结果。试验结果表明：单全球定位系统，单北斗系统及其组合的平面定位精度在毫米级至厘米级，高程定位精度在厘米级；双卫星导航组合定位与单全球定位系统相比，平面定位精度相近，高程方向定位精度提升了27.90％，但由于北斗系统的加入，导致标准差增大；单北斗系统因为 U 方向收敛速度过慢导致收敛时间远大于单全球定位系统收敛时间，双卫星导航组合定位收敛时间较单全球定位系统缩短19.38％；双卫星导航组合精密单点定位因为可用卫星数目多，卫星空间几何结构稳定，能较好的应对诸如遮挡严重等突发状况。%The three-system observed data in Tianjin CORS was calculated by the self-written software,the static precise point positioning (PPP)results of three approaches including GPS PPP、BDS PPP and GPS/BDS PPP were analyzed.The re-sults show that the accuracy of GPS PPP、BDS PPP and GPS/BDS PPP can achieve mm to cm-level in horizontal direction and cm-level in vertical direction.Compared to GPS PPP,the horizontal positioning accuracy of GPS/BDS PPP is close and its ver-tical positioning accuracy improved 27.90%.But the standard deviation was increased for GPS PPP due to BDS observed data was added.The convergence time of BDS PPP is much larger than GPS PPP because the convergence speed of BDS PPP is too slow in vertical direction.After adding BDS,the convergence time can be reduced by 19.38% compared with GPS PPP.For GPS/BDS PPP,the available number of satellites is more and the geometry structure of satellites is more stable than GPS PPP,therefore it can better deal with the unexpected situations such as shelter conditions.